U.S. patent number 10,770,607 [Application Number 16/067,086] was granted by the patent office on 2020-09-08 for interconnected photovoltaic module configuration.
This patent grant is currently assigned to FLISOM AG. The grantee listed for this patent is FLISOM AG. Invention is credited to Andreas Bogli, Ivan Sinicco, Stephan Stutterheim.
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United States Patent |
10,770,607 |
Stutterheim , et
al. |
September 8, 2020 |
Interconnected photovoltaic module configuration
Abstract
Embodiments of the present disclosure generally relate to an
apparatus and method of forming a photovoltaic module assembly that
contains a plurality of interconnected photovoltaic modules that
are used to generate an amount of power when exposed to
electromagnetic radiation. The formed photovoltaic module assembly
will generally include two or more photovoltaic modules that can
generate and deliver power to an external grid, external network or
external device. The photovoltaic module assembly can be a stand
alone power generating device or be disposed within an array of
interconnected photovoltaic devices.
Inventors: |
Stutterheim; Stephan
(Wallisellen, CH), Bogli; Andreas (Vogelsang,
CH), Sinicco; Ivan (Altendorf, CH) |
Applicant: |
Name |
City |
State |
Country |
Type |
FLISOM AG |
Niederhasli |
N/A |
CH |
|
|
Assignee: |
FLISOM AG (Niederhasli,
CH)
|
Family
ID: |
1000005044254 |
Appl.
No.: |
16/067,086 |
Filed: |
January 4, 2017 |
PCT
Filed: |
January 04, 2017 |
PCT No.: |
PCT/IB2017/000005 |
371(c)(1),(2),(4) Date: |
June 28, 2018 |
PCT
Pub. No.: |
WO2017/118904 |
PCT
Pub. Date: |
July 13, 2017 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
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US 20190027625 A1 |
Jan 24, 2019 |
|
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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62275585 |
Jan 6, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
1/00135 (20130101); H01L 31/046 (20141201); H01L
31/03926 (20130101); A61B 1/126 (20130101); H01L
31/18 (20130101); H01L 31/042 (20130101); H02S
40/36 (20141201); H01L 31/0749 (20130101); A61B
90/70 (20160201); Y02E 10/541 (20130101); A61B
1/00142 (20130101); G02B 23/2476 (20130101) |
Current International
Class: |
H01L
31/0392 (20060101); H01L 31/18 (20060101); H02S
40/36 (20140101); H01L 31/042 (20140101); A61B
90/70 (20160101); A61B 1/00 (20060101); H01L
31/0749 (20120101); H01L 31/046 (20140101); A61B
1/12 (20060101); G02B 23/24 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Machine Translation Kessler DE 1019643--Accessed Oct. 25, 2019
(Year: 2002). cited by examiner .
International Search Report and Written Opinion for
PCT/IB2017/000005, dated Mar. 27, 2017. cited by applicant.
|
Primary Examiner: Gardner; Shannon M
Attorney, Agent or Firm: Patterson & Sheridan, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No.
PCT/IB2017/000005, filed Jan. 4, 2017, which is a continuation of
U.S. Application No. 62/275,585, filed Jan. 6, 2016. The above
applications are all incorporated by reference herein.
Claims
What is claimed is:
1. A photovoltaic module assembly, comprising: a front sheet; a
back sheet; an array of photovoltaic modules disposed between the
front sheet and the back sheet, each of the photovoltaic modules
are separated from one another by a first length, wherein each
photovoltaic module comprises two or more sub-modules that each
have a cathode region and an anode region, and wherein the anode
region is disposed at an opposite end of the photovoltaic module
from the cathode region, adjacent sub-modules within each
photovoltaic module are separated by a second length, and the first
length is greater than the second length; a first busbar that is
aligned in a first direction, and is electrically coupled to the
cathode region of each sub-module; and a second busbar that is
aligned in the first direction, and is electrically coupled to the
anode region of each sub-module.
2. The photovoltaic module assembly of claim 1, wherein each of the
photovoltaic modules further comprise: a flexible substrate; and
the two or more sub-modules each comprise a plurality of thin-film
layers that are disposed on the flexible substrate.
3. The photovoltaic module assembly of claim 2, wherein the front
sheet and the flexible substrate comprise a polymer, and the back
sheet comprises a flexible material.
4. The photovoltaic module assembly of claim 3, further comprising:
a third layer disposed between the back sheet and the photovoltaic
module, wherein the third layer comprises a polymer; and a fourth
layer disposed between the front sheet and the photovoltaic module,
wherein the fourth layer comprises a polymer.
5. The photovoltaic module assembly of claim 1, wherein: the two or
more sub-modules each include an array of photovoltaic cells, and
the array of photovoltaic cells extends in a second direction from
the cathode region to the anode region, the second direction
substantially perpendicular to the first direction.
6. The photovoltaic module assembly of claim 1, further comprising
a junction box disposed at a first end of the array of photovoltaic
modules.
7. A photovoltaic module assembly, comprising: a front sheet; a
back sheet; an array of photovoltaic modules disposed between the
front sheet and the back sheet, each of the photovoltaic modules
are separated from one another by a first length, wherein each
photovoltaic module comprises two or more sub-modules that each
have a cathode region and an anode region, wherein adjacent
sub-modules within each photovoltaic module are separated by a
second length, the first length is greater than the second length,
and the anode region is disposed at an opposite end of the
photovoltaic module from the cathode region, each sub-module
comprising: an array of photovoltaic cells extending in a second
direction from the cathode region to the anode region, each of the
photovoltaic cells separated from one another by a third length,
wherein the third length is smaller than the second length; a first
busbar that is aligned in a first direction, and is electrically
coupled to the cathode region of each sub-module; and a second
busbar that is aligned in the first direction, and is electrically
coupled to the anode region of each sub-module.
8. The photovoltaic module assembly of claim 7, wherein the
photovoltaic modules each further comprise: a flexible substrate;
and the two or more sub-modules each comprise a plurality of
thin-film layers that are disposed on the flexible substrate.
9. The photovoltaic module assembly of claim 8, wherein the front
sheet and the flexible substrate comprise a polymer, and the back
sheet comprises a flexible material.
10. The photovoltaic module assembly of claim 9, further
comprising: a third layer disposed between the back sheet and the
photovoltaic module, wherein the third layer comprises a polymer;
and a fourth layer disposed between the front sheet and the
photovoltaic module, wherein the fourth layer comprises a
polymer.
11. The photovoltaic module assembly of claim 7, wherein: the two
or more sub-modules each include an array of photovoltaic cells,
and the array of photovoltaic cells extends in a second direction
from the cathode region to the anode region, the second direction
substantially perpendicular to the first direction.
12. The photovoltaic module assembly of claim 7, further comprising
a junction box disposed at a first end of the array of photovoltaic
modules.
13. A photovoltaic module assembly, comprising: a front sheet
having a first end and a second end, which is opposite to the first
end; a back sheet having a first end and a second end, which is
opposite to the first end; an array of photovoltaic modules
disposed between the front sheet and the back sheet, wherein the
array of photovoltaic modules are positioned in a first direction
between the first end of the front sheet and the back sheet and the
second end of the front sheet and the back sheet, a gap is formed
in the first direction between adjacent edges of adjacent
photovoltaic modules disposed within the array, an edge of a first
photovoltaic module of the array of photovoltaic modules, disposed
closest to the first end of the front sheet and the back sheet, is
positioned a first end length from the first end of the front sheet
and the back sheet, the first end length is larger than the gap,
and each photovoltaic module comprises two or more sub-modules that
each have a cathode region and an anode region, and wherein the
anode region is disposed at an opposite end of the photovoltaic
module from the cathode region; a first busbar that is aligned in
the first direction, and is electrically coupled to the cathode
region of each sub-module; and a second busbar that is aligned in
the first direction, and is electrically coupled to the anode
region of each sub-module.
14. The photovoltaic module assembly of claim 13, wherein each of
the photovoltaic modules further comprise: a flexible substrate,
and two or more sub-modules that comprise a plurality of thin-film
layers that are disposed on the flexible substrate.
15. The photovoltaic module assembly of claim 14, wherein the front
sheet and the flexible substrate comprise a polymer, and the back
sheet comprises a flexible material.
16. The photovoltaic module assembly of claim 15, further
comprising: a third layer disposed between the back sheet and the
photovoltaic module, wherein the third layer comprises a polymer;
and a fourth layer disposed between the front sheet and the
photovoltaic module, wherein the fourth layer comprises a
polymer.
17. The photovoltaic module assembly of claim 13, wherein: the two
or more sub-modules each include an array of photovoltaic cells,
and the array of photovoltaic cells extends in a second direction
from the cathode region to the anode region, the second direction
substantially parallel to the first direction.
18. The photovoltaic module assembly of claim 13, further
comprising a junction box disposed at the first end of the front
sheet and the back sheet.
19. The photovoltaic module assembly of claim 13, wherein at least
one of the photovoltaic modules is configured to be removed from
the photovoltaic module assembly.
20. The photovoltaic module assembly of claim 13, wherein the first
and second busbar each comprise a plurality of conductive strips.
Description
BACKGROUND
Field
Embodiments of the present disclosure generally relate to an
apparatus and method of forming an interconnected photovoltaic
module device.
Description of the Related Art
Photovoltaic devices generally include one or more photovoltaic
modules that include arrays of interconnected photovoltaic cells.
Photovoltaic modules can be classified according to the materials
which are used in the photovoltaic cells. Thin-film photovoltaic
cells are an alternative design to the traditional crystalline
silicon-based design for photovoltaic cells. Examples of thin-film
photovoltaic cells include solar cells including at least one
thin-film absorber layer. The thin-film absorber layer may, for
example, comprise one layer of amorphous silicon, cadmium telluride
(CdTe), and copper indium gallium selenide (CIGS). Thin-film
photovoltaic modules are generally composed of a number of
electrically interconnected optoelectronic components, such as
photovoltaic cells. Thin-film-photovoltaic cells are generally
composed of a stack of three material layers: (1) a conducting
back-contact electrode layer, (2) a semiconductive photovoltaic
material layer, also known as the absorber, and (3) a conducting
front-contact electrode layer, where the front-contact layer is
usually transparent.
One advantage available when making thin-film photovoltaic devices
is the option of using monolithic integration, which is the
interconnection of several optoelectronic components on a single
substrate. Monolithic integration includes a sequence of layer
deposition and scribing steps to form the individual photovoltaic
cells. Photovoltaic cells based on thin-film semiconductive
materials, such as CIGS or CdTe, show promise for less expensive
solar electricity, lower energy payback time, a greater range of
applications, and improved life-cycle impact as compared to
traditional wafer-based silicon photovoltaic devices or solar
cells. Compared to wafer-based photovoltaic devices, thin-film
monolithic photovoltaic modules may have lower production costs due
to reduced material quantities required to form thin film solar
cells, reduced labor costs, and ease of automatic production of
large quantities of photovoltaic modules, such as using
roll-to-roll manufacturing techniques.
Another advantage available when making thin-film photovoltaic
devices is the option of making the devices flexible. Flexible
thin-film photovoltaic devices may be formed by encapsulating a
flexible photovoltaic module component within layers of polymer and
other materials to form a larger photovoltaic module assembly that
includes multiple photovoltaic modules. Flexible thin-film
photovoltaic devices have many desirable applications that are not
available to most conventional crystalline silicon wafer type solar
cells or glass substrate thin-film photovoltaic applications. For
example, flexible solar cells may be used in building integrated
photovoltaic (BIPV) applications and/or on clothing, flexible
canopies, or other non-rigid supporting member type applications.
In various commercial BIPV applications, the length of the formed
photovoltaic module assemblies often need to be customized to meet
the BIPV application's power requirements and/or form an
aesthetically pleasing array of photovoltaic module assemblies.
Such BIPV type photovoltaic module assemblies might be produced in
lengths of up to 20 meters, and generate high output voltages.
However, flexible photovoltaic devices are ordinarily thinner than
glass-encapsulated photovoltaic devices and may be subject to
greater stresses and strains due to flexing during installation
and/or normal use, which may cause damage to the encapsulated
electrical and photovoltaic module components. Due to stress and
strain induced in a formed photovoltaic module, and normal
production yield issues, one or more of the photovoltaic modules
within a formed photovoltaic module assembly can become damaged
and/or inoperable, which can render the whole photovoltaic module
assembly unusable. Therefore there is a need for a photovoltaic
module assembly that can be reworked to make it functional again to
avoid having to scrap the whole photovoltaic module assembly when
one of many photovoltaic modules becomes inoperable.
Therefore, there is a need for an apparatus and method of forming a
cost effective and reliable thin-film photovoltaic device that
solves the problems described above.
SUMMARY
Embodiments of the disclosure may provide a flexible photovoltaic
apparatus, comprising a front sheet, a back sheet, an array of
photovoltaic modules disposed between the front sheet and the back
sheet, a first busbar that is aligned in the first direction, and
is electrically coupled to the cathode region of each sub-module in
each photovoltaic module, and a second busbar that is aligned in
the first direction, and is electrically coupled to the anode
region of each sub-module. The array of photovoltaic modules
include a gap that is formed in a first direction between adjacent
edges of adjacent photovoltaic modules disposed within the array.
Each photovoltaic module will also include two or more sub-modules
that each have a cathode region and an anode region, and wherein
the anode region is disposed at an opposite end of the photovoltaic
module from the cathode region.
Embodiments of the disclosure may further provide a method of
forming a photovoltaic module, comprising disposing an array of
photovoltaic modules on a first adhesive layer that is disposed
over a back sheet, disposing a portion of a first busbar over the
cathode region of each sub-module, wherein the first busbar is
aligned in the first direction, disposing a portion of a second
busbar over the anode region of each sub-module, wherein the second
busbar is aligned in the first direction, disposing a second
adhesive layer over the first busbar, the second busbar, the array
of photovoltaic modules, the first adhesive layer and the back
sheet, disposing a front sheet over the second adhesive layer, and
laminating the front sheet, the second adhesive layer, the first
busbar, the second busbar, the array of photovoltaic modules, the
first adhesive layer and the back sheet to encapsulate the
photovoltaic modules. The array of photovoltaic modules include a
gap that is formed in a first direction between adjacent edges of
adjacent photovoltaic modules disposed within the array. Each
photovoltaic module will also include two or more sub-modules that
each have a cathode region and an anode region, and wherein the
anode region is disposed at an opposite end of the photovoltaic
module from the cathode region.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the
present disclosure can be understood in detail, a more particular
description of the disclosure, briefly summarized above, may be had
by reference to embodiments, some of which are illustrated in the
appended drawings. It is to be noted, however, that the appended
drawings illustrate only exemplary embodiments and are therefore
not to be considered limiting of its scope, and may admit to other
equally effective embodiments.
FIG. 1A is an isometric view of a photovoltaic module assembly,
according to one embodiment of the disclosure.
FIG. 1B is a side sectional view of a portion of a photovoltaic
module disposed within the photovoltaic module assembly illustrated
in FIG. 1A, according to an embodiment of the disclosure.
FIG. 1C is a side sectional view of another portion of a
photovoltaic module disposed within the photovoltaic module
assembly illustrated in FIG. 1A, according to an embodiment of the
disclosure.
FIG. 1D is a schematic view of a photovoltaic module assembly
forming apparatus, according to an embodiment of the
disclosure.
FIG. 2A is a side sectional view of an end of the photovoltaic
module assembly illustrated in FIG. 1A, according to one embodiment
of the disclosure.
FIG. 2B is a side sectional view of an end of the photovoltaic
module assembly illustrated in FIG. 1A, according to one embodiment
of the disclosure.
FIGS. 3A-3C are top views of different configurations of
photovoltaic module assemblies, according to embodiments of the
disclosure.
FIG. 3D is a side sectional view of a portion of a photovoltaic
module disposed within a photovoltaic module assembly, according to
an embodiment of the disclosure.
FIG. 4A is a top view of a photovoltaic module assembly, according
to an embodiment of the disclosure.
FIG. 4B is a top view of the photovoltaic module assembly
illustrated in FIG. 4A that has a damaged photovoltaic module
removed therefrom, according to an embodiment of the
disclosure.
FIG. 4C is a top view of a reconfigured version of the photovoltaic
module assembly illustrated in FIG. 4A, according to an embodiment
of the disclosure.
FIG. 5A is a side sectional view of two reworked portions of a
photovoltaic module assembly, according to an embodiment of the
disclosure.
FIG. 5B is a side sectional view of the two reworked portions of
the photovoltaic module assembly, which is illustrated in FIG. 5A,
in an electrically connected configuration, according to an
embodiment of the disclosure.
FIG. 5C is a side sectional view of an alternate electrically
connected configuration of the two reworked portions of the
photovoltaic module assembly, according to an embodiment of the
disclosure.
To facilitate understanding, identical reference numerals have been
used, where possible, to designate identical elements that are
common to the figures. It is contemplated that elements and
features of one embodiment may be beneficially incorporated in
other embodiments without further recitation.
DETAILED DESCRIPTION
Embodiments of the present disclosure generally relate to an
apparatus and method of forming a photovoltaic module assembly that
contains a plurality of interconnected photovoltaic modules that
are used to generate a desired amount of power when exposed to
electromagnetic radiation. The formed photovoltaic module assembly
will generally include two or more photovoltaic modules that can
generate and deliver power to an external grid, external network or
external device. The photovoltaic module assembly can be a stand
alone power generating device or be disposed within an array of
interconnected photovoltaic devices.
FIG. 1A is an isometric view of a photovoltaic module assembly 100,
according to one embodiment of the disclosure. The photovoltaic
module assembly 100 may include multiple optoelectronic devices,
such as photovoltaic devices (e.g., solar cells), diodes, and LEDs.
In some embodiments, the photovoltaic module assembly 100 includes
two or more photovoltaic modules 110 that are interconnected by a
plurality of busbars 170, such as busbars 170A and 170B. The
busbars 170A and 170B are disposed in a spaced apart relationship
along the length L of the photovoltaic module assembly 100. The
interconnected photovoltaic modules 110 and busbars 170 are
encapsulated to protect these current generating and/or current
carrying electrical components from the external environment during
normal use. Each photovoltaic module 110 includes one or more
photovoltaic sub-modules, such as the photovoltaic sub-modules
1101, 1102, and 1103 illustrated in FIG. 1A. In one example, a
photovoltaic module 110 includes two or more photovoltaic
sub-modules, which are hereafter referred to as sub-modules, such
as three to five sub-modules.
In some embodiments, the sub-modules are monolithically formed on a
substrate by use of multiple photovoltaic device forming steps.
FIG. 1B is a side sectional view of a portion of the sub-module
1101 of the first photovoltaic module 110 disposed within the
photovoltaic module assembly 100 shown in FIG. 1A. In some
embodiments, the sub-modules within each photovoltaic module 110
are formed on a substrate 111. The substrate 111 may be a flexible
substrate, a rigid substrate, or semi-rigid material containing
substrate (e.g., semi-rigid substrates distort under their own
weight, but are unable to be formed in a roll form), and is
typically formed from an electrically insulating material. In one
example, a flexible substrate material may be used to form the
substrate 111, such as a substrate formed from a polyimide
material. In one example, the polyimide substrate has a thickness
in the Z-direction from about 5 micrometers (.mu.m) to about 200
.mu.m, such as from about 15 .mu.m to about 100 .mu.m.
In some embodiments, each sub-module within each photovoltaic
module 110 may include a plurality of thin-film layers that are
deposited on the substrate 111, and then patterned (e.g., scribed)
to form a plurality of monolithically interconnected photovoltaic
cells 112 that are electrically connected in series. In other
embodiments, the sub-modules can include a photovoltaic device
formed on another substrate that is then positioned on the
substrate 111.
A sub-module can include, for example, a back-contact layer 120
formed on the substrate 111, an absorber layer 130 formed over the
back-contact layer 120, and a front-contact layer 150 formed over
the absorber layer 130. The back-contact layer 120 can be
fabricated from a material having a high optical reflectance and is
commonly made of molybdenum (Mo) although several other thin-film
materials, such as metal chalcogenides, molybdenum chalcogenides,
molybdenum selenides (such as MoSe.sub.2), sodium (Na)-doped Mo,
potassium (K)-doped Mo, Na- and K-doped Mo, transition metal
chalcogenides, tin-doped indium oxide (ITO), doped or non-doped
indium oxides, doped or non-doped zinc oxides, zirconium nitrides,
tin oxides, titanium nitrides, titanium (Ti), tungsten (W),
tantalum (Ta), gold (Au), silver (Ag), copper (Cu), and niobium
(Nb) may also be used or included advantageously. In some
embodiments, the back-contact layer 120 is deposited onto the
substrate 111 by use of sputtering process.
The absorber layer 130 is typically made of an "ABC" material,
wherein "A" represents elements in group 11 of the periodic table
of chemical elements as defined by the International Union of Pure
and Applied Chemistry including copper (Cu) or silver (Ag), "B"
represents elements in group 13 of the periodic table including
indium (In), gallium (Ga), or aluminum (Al), and "C" represents
elements in group 16 of the periodic table including sulfur (S),
selenium (Se) or tellurium (Te). An example of an ABC material is
the Cu(In,Ga)Se.sub.2 semiconductor also known as CIGS. In some
embodiments, the absorber layer may include a polycrystalline
material. In other embodiments, the absorber layer may be a
monocrystalline material. Another example of a material that may be
used as the absorber layer is chalcopyrite.
The front-contact layer 150 can be an electrically conductive and
optically transparent material, such as a transparent conductive
oxide (TCO) layer. For example, in some embodiments, the
front-contact layer 150 may be formed of doped or non-doped
variations of materials, such as indium oxides, tin oxides, or zinc
oxides.
In some embodiments, a semiconductive buffer layer 140 can be
disposed between the absorber layer 130 and the front-contact layer
150. The semiconductive buffer layer 140 ordinarily has an energy
bandgap higher than 1.5 eV. The semiconductive buffer layer may be
formed of materials, such as CdS, Cd(S,OH), CdZnS, indium sulfides,
zinc sulfides, gallium selenides, indium selenides, compounds of
(indium, gallium)-sulfur, compounds of (indium, gallium)-selenium,
tin oxides, zinc oxides, Zn(Mg,O)S, Zn(O,S) material, or variations
thereof.
FIGS. 1A and 1B illustrate photovoltaic modules 110 that each
include three sub-modules 1101, 1102 and 1103 that contain an array
of photovoltaic cells 112 that extends in the Y-direction from a
first end region 108A to a second end region 108B within the
photovoltaic module 110. As shown in FIG. 1B, the photovoltaic
cells 112 are spaced apart in the Y-direction and consecutive
photovoltaic cells (e.g., adjacent photovoltaic cells 112) are
interconnected to each other by a plurality of serial interconnects
112A (i.e., also referred to as P1, P2 and P3 scribe lines), that
extend in the X-direction. The layers of each photovoltaic cell
112, such as layers 120-150, are formed in a stacked orientation in
the Z-direction (the third direction). The photovoltaic cells 112
in each sub-module (e.g., sub-module 1102) are also isolated from
other photovoltaic cells 112 disposed in adjacent sub-modules
(e.g., sub-modules 1101 and 1103) by use of one or more isolation
scribe lines 113 that are aligned in the Y-direction, and are used
to separate the sub-modules. The photovoltaic cells 112 are
electrically connected in series between busbars 170A and 170B by
use of the formed serial interconnects 112A.
The serial interconnect 112A forms an electrical connection between
each consecutive photovoltaic cell 112 in the array of cells. Each
serial interconnect 112A includes a connecting groove 161 (i.e.,
the P2 scribe line) that is formed through the front-contact layer
150, the semiconductive buffer layer 140 and the absorber layer 130
to form an electrically conductive path that electrically serially
connects consecutive photovoltaic cells in the array. The
conductive path may be formed by melting a portion of the absorber
layer 130 during a laser scribing process used to form the
connecting groove 161. For example, one connecting groove 161
electrically connects the front-contact layer 150 of the third
photovoltaic cell 112 to the back-contact layer 120 of the fourth
photovoltaic cell 112.
In some embodiments, each serial interconnect 112A includes a pair
of grooves to electrically isolate portions of each adjacent
photovoltaic cell. A back-contact groove 121 (i.e., the P1 scribe
line) electrically isolates the back-contact layers 120 of adjacent
photovoltaic cells 112 from each other. A front-contact groove 141
(i.e., the P3 scribe line) electrically isolates the front-contact
layers 150 of adjacent photovoltaic cells from each other. The
serial interconnects 112A can thus be used to electrically connect
the photovoltaic cells 112 in series.
Referring back to FIG. 1A, in some embodiments, photovoltaic module
assembly 100 includes two or more busbars 170, such as busbars 170A
and 170B, that are used to interconnect the photovoltaic modules
110 disposed within the photovoltaic module assembly 100. The power
generated by the photovoltaic cells 112 in the sub-modules within
each photovoltaic module 110 is collected by the two or more
busbars and delivered to an external power connection (not shown)
that is formed within a junction box 190 disposed at one end of the
photovoltaic module assembly 100. As noted above, each photovoltaic
module 110 disposed within the photovoltaic module assembly 100 may
be selected (e.g., binned) so that the output of all of the
photovoltaic modules 110 in the photovoltaic module assembly 100
have similar performance characteristics to assure that the overall
output of the photovoltaic module assembly 100 can be optimized.
The photovoltaic module assembly performance characteristics may be
determined by use of an analysis process that measures a
performance characteristic of sub-modules, such as conversion
efficiency (CE), photocurrent (I), series resistance (R.sub.s),
fill factor (FF), sheet resistance (.rho.), open circuit voltage
(V.sub.oc), dark current (I.sub.dc), short circuit current
(I.sub.sc), quantum efficiency (QE), maximum power (P.sub.max),
maximum current (I.sub.max), maximum voltage (V.sub.max) and/or
spectral response.
In some embodiments, the photovoltaic module assembly 100 is
configured such that the photovoltaic modules 110 in the
photovoltaic module assembly 100 are electrically connected in
parallel, such that, for example, when exposed to light the
cathodic end of the sub-modules within all of the photovoltaic
modules 110 are connected together by the first busbar 170A and the
anodic end of the submodules in all of the photovoltaic modules 110
are connected together by the second busbar 170B. The cathodic end
may be associated with the first end region 108A and the anodic end
is associated with the second end region 108B. In this case, the
series connected photovoltaic cells 112 within each sub-module
generate a voltage difference between the first busbar 170A and the
second busbar 170B during normal operation. In one example, each
sub-module includes a plurality of photovoltaic cells 112 that form
a voltage between about 0.5 volts and about 1000 volts between the
busbars 170A and 170B and a current of between 100 milliamps (mA)
and 4000 mA during normal operation. However, in some embodiments,
it may alternately be desirable to connect the photovoltaic modules
110 in series, such that the voltage generated by the sub-modules
in the photovoltaic modules 110 adds along the length L (FIG. 1A)
of the photovoltaic module assembly 100.
In general, the busbars 170 may be formed from a variety of
materials including metals, such as copper, nickel plated copper,
silver plated copper, tin plated copper, steel, stainless steel, or
other commonly used conductors. The busbars 170 can have a width in
the Y-direction (FIG. 1A) that is from about 100 .mu.m to about 3
centimeters (cm), such as from about 2 millimeters (mm) to about 8
mm, such as from about 3 mm to about 5 mm. Furthermore, the busbars
170 can have a thickness in the Z-direction from about 0.05 mm to
about 2 mm, such as from about 0.1 mm to about 1 mm, such as from
about 0.15 mm to about 0.3 mm.
Each of the busbars 170 is in electrical communication with a
portion of each of the sub-modules in a photovoltaic module. In one
example, the first busbar 170A is electrically coupled to a portion
of the back-contact layer 120 at a first end (e.g., end region
108A) of the submodules through a connection region formed between
the front-contact layer 150 and the back-contact layer 120.
Similarly, in this example, the second busbar 170B may be
electrically coupled to a portion of the front-contact layer 150
disposed at an opposing end (e.g., end region 108B) of each of the
sub-modules. In some embodiments, regions of the busbars 170A and
170B are bonded to their respective portion of the sub-modules by
use of a bonding material, such as a conductive adhesive, solder
material or other similar material, and/or a bonding process (e.g.,
thermal bonding, ultrasonic bonding) that is used to form an
electrical contact between a portion of the busbars and the
conductive portions of the sub-modules.
As noted above, the photovoltaic modules 110 and busbars 170 are
encapsulated within the photovoltaic module assembly 100 by use of
a front-side adhesive 101A and a back-side adhesive 101B. In some
embodiments, the front-side adhesive 101A and the back-side
adhesive 101B completely surround and encapsulate each of the
photovoltaic modules 110 and busbars 170. In one example, the
front-side adhesive 101A is formed over the front-contact layer 150
of each of the sub-modules, and also over the first and second
busbars 170A and 170B. The front-side adhesive 101A may be formed
of a flexible material, such as a flexible polymer. For example, in
one embodiment the front-side adhesive 101A may be formed from EVA,
a thermoplastic olefin (TPO) based polymer or a TPO blend.
The back-side adhesive 101B is disposed over the side of the
substrate 111 that is opposite to the side that the sub-module(s)
is formed on. The back-side adhesive 101B may be formed of a
flexible material, such as a flexible polymer. For example, in one
embodiment the back-side adhesive 101B may be formed from EVA, a
thermoplastic olefin-based polymer (TPO) or a TPO polymer blend.
The back-side adhesive 101B may contact the front-side adhesive
101A at each of the ends of the photovoltaic modules and also on
the sides of the photovoltaic modules, so that the front-side
adhesive 101A and the back-side adhesive 101B completely surround
and encapsulate the photovoltaic modules.
A front sheet 151 can be disposed on an outer surface of the
front-side adhesive 101A, such as a top surface of the front-side
adhesive 101A. The front sheet 151 can be formed of a transparent
material, such as a transparent thermoplastic polymer. In some
embodiments, the front sheet 151 may be formed of a flexible
material. In some embodiments, a flexible front sheet 151 may have
a thickness in the Z-direction from about 0.005 mm to about 1 mm.
However, in some embodiments, the front sheet 151 may be formed of
a rigid material or semi-rigid material.
A back sheet 109 can be disposed on an outer surface of the
back-side adhesive 101B, such as a bottom surface of the back-side
adhesive 101B. The back sheet 109 may include a reflective
material, such as a metal layer, a reflective polymer or a polymer
with a reflective layer (e.g., metal foil) formed over a first
surface that is adjacent to the bottom surface of the back-side
adhesive 101B. In some embodiments, the back sheet 109 may be
formed from a flexible material (e.g., flexible polymer layer
and/or flexible metal foil). In some embodiments, the back sheet
109 may include a fiber-reinforced polymer material. In some
embodiments, a flexible back sheet 109 may have a thickness in the
Z-direction from about 0.005 mm to about 3 mm. However, in some
embodiments, the back sheet 109 may be formed of a rigid or
semi-rigid material.
In some embodiments, as schematically illustrated in FIG. 10, the
photovoltaic module assembly 100 may include one or more bypass
diodes 199 that are designed to prevent the effects of hot-spot
heating. The bypass diode 199 is integrated within the encapsulated
portion of the photovoltaic module assembly 100 during
manufacturing and is connected in parallel, but with an opposite
polarity to the sub-modules as shown in FIG. 1C. In some
configurations, the leads of a bypass diode 199 are electrically
connected to the first and second busbars 170A and 170B by use of a
bonding technique, such as a soldering technique.
The photovoltaic module assembly 100 may also include an insulation
end seal 105 that is disposed at one end of the photovoltaic module
assembly 100, as illustrated in FIG. 2A. The insulation end seal
105 may include a portion of the edge seal 301 that is disposed
over the end 102 of the photovoltaic module assembly 100. The
presence of the edge seal 301 at the end 102 can be used to assure
that the first and second busbars 170A and 170B that typically
extend to the end 102 of the photovoltaic module assembly 100 are
not exposed to the external environment. In some configurations,
the edge seal 301 may also be disposed on one or both sides 104 of
the formed photovoltaic module assembly 100, as illustrated in FIG.
1B. The presence of the edge seal 301 at the end 102 and sides 104
of the photovoltaic module assembly 100 can be used to assure that
photovoltaic module assembly 100 will meet electrical certification
requirements and eliminate common photovoltaic apparatus
manufacturing and photovoltaic device failure modes. In general,
the edge seal 301 comprises a polymeric material, such as an
elastomer, for example a butyl rubber that can be formed by
dispensing a liquid precursor material along the edge of the
photovoltaic module assembly 100 and allowing it to cure. The edge
seal 301 can be formed of a material having a low water vapor
transmission rate (WVTR), such as WVTR less than about
1.times.10.sup.-4 (g/m.sup.2day). The edge seal 301 may also be
protected by a "clamp" or termination box that is disposed over a
portion of the front sheet 151 and the back sheet 109 along one or
more of the ends and/or edges of the photovoltaic module assembly
100. The "clamp" or termination box may be made out of a rigid
material like a thermoplastic material.
The photovoltaic module assembly 100 may further include a junction
box 190 that is disposed at one end of the photovoltaic module
assembly 100, as illustrated in FIG. 2B. The junction box 190 may
include a region 192 that allows the portions of the busbars 170
disposed at the end 103 of the photovoltaic module assembly 100 to
be electrically connected to one or more external devices, such as,
for example, electronics used to charge one or more external
batteries. In some configurations, one or more walls 191 of the
junction box 190 may be positioned over the end 103 of the
photovoltaic module assembly 100 to sealably enclose a region 192.
The first and second busbars 170A and 170B may extend into the
junction box 190 past the end 103 of the photovoltaic module
assembly 100 to allow for an electrical connection to be made to
the busbars within the region 192 of the junction box 190. In some
configurations, the walls 191 of the junction box 190 may be
adhesively bonded to the surface of the back sheet 109, the sides
104 of the photovoltaic module assembly 100 and a surface of the
front sheet 151 by use of an adhesive and/or potting material to
form an environmental seal therebetween. The junction box 190 may
include one or more connectors for connecting the first busbars
170A and 1706 with one or more external conductors (not shown) that
are disposed through a sealable opening 193 of the junction box
190.
FIG. 1D is a schematic view of an apparatus 125 that may be used to
form a photovoltaic module assembly described herein. The apparatus
125 illustrated in FIG. 1D is not intended to be limiting as to the
scope of the disclosure provided herein, but is intended to
schematically illustrate an apparatus that may be used to form a
photovoltaic module assembly, such as the photovoltaic module
assembly 100 illustrated in FIG. 1A, by use of an automated or
semi-automated process sequence. The apparatus 125 may include a
back-sheet roll 107A, a back-side adhesive layer roll 107B, two or
more busbar rolls 107C, an front-side adhesive layer roll 107D, a
front-sheet roll 107E, material guiding rollers, a controller 106A
and a conveyor system 106B. The controller 106A and conveyor system
106B are configured to help control the transportation of portions
of the various materials contained in the rolls 107A-107E to form a
photovoltaic module assembly using an automated or semi-automated
process sequence. In some configurations, the controller 106A may
include a central processing unit (CPU) (not shown), memory (not
shown), and support circuits (or I/O) (not shown). The CPU may be
one of any form of computer processors that are used in industrial
settings for controlling various system processes and hardware
(e.g., conveyors, dispensing devices, robotics, etc.) and monitor
the system and related transport processes (e.g., sub-module
position, detector signals, etc.). The memory is connected to the
CPU, and may be one or more of a readily available memory, such as
flash memory, random access memory (RAM), read only memory (ROM),
floppy disk, hard disk, or any other form of non-volatile digital
storage, local or remote. Software instructions and data can be
coded and stored within the memory for instructing the CPU. The
support circuits are also connected to the CPU for supporting the
processor in a conventional manner. A program (or computer
instructions) readable by the controller 106A determines which
tasks and/or processes are performable in the apparatus 125.
The photovoltaic module assembly formation process sequence
performed by the apparatus 125 may first include individually
placing the tested and sorted photovoltaic modules 110, with the
thin-film layer side facing up, on a portion of back-side adhesive
layer 101B that is disposed over a portion of the back sheet 109.
The portions of the back-side adhesive layer 101B and the back
sheet 109 on which the photovoltaic modules 110 are placed are
delivered or rolled out from their respective rolls 107B and
107A.
Two or more busbars 170, which are spaced apart in the Y direction,
are then dispensed from the two or more busbar rolls 107C (only one
shown) over a surface of each of the photovoltaic modules 110. The
two or more busbars can be disposed over the end regions 108A and
108B of the photovoltaic modules 110 in this step as the conveyor
system 106 moves the photovoltaic modules 110, back-side adhesive
layer 101B and the back sheet 109 in the +X-direction.
Next, a portion of the front-side adhesive layer 101A is then
disposed over the busbars 170, photovoltaic module 110, back-side
adhesive layer 101B and portion of the back sheet 109, by use of
the controller 106A, conveyor system 106B and front-side adhesive
layer roll 107D.
Next, a portion of the front-sheet 151 is then disposed over the
front-side adhesive layer 101A, busbars 170, photovoltaic module
110, back-side adhesive layer 101B and portion of the back sheet
109, by use of the conveyor system 106 and front-sheet layer roll
107E.
The layers used to form the photovoltaic module assembly 100 are
then laminated together to form at least part of one or more
encapsulated photovoltaic module assemblies. The lamination process
may be performed in a lamination module 185. The lamination process
will typically include the delivery of heat, such as radiant heat
from a lamp 187, and the application of pressure. In some
embodiments, pressure may be applied to the various module assembly
layers by applying a controlled force F using an actuator (not
shown) and roller 186. The photovoltaic module assemblies 100
having a desirable length can then be sectioned from the continuous
encapsulated photovoltaic module containing roll created by the
apparatus 125. Two formed photovoltaic module assemblies 100 that
are disposed within the encapsulated photovoltaic module containing
roll can be separated from each other at an interconnection region
310 (FIGS. 3A-3C) formed between the last photovoltaic module in
one photovoltaic module assembly and the first photovoltaic module
in a second photovoltaic module assembly. Details of the
interconnection region and sectioning process are discussed in
greater detail below. Alternately, the lamination process may be
performed in a batch process that includes sectioning the
photovoltaic module assemblies 100 from the continuous encapsulated
photovoltaic module containing roll created by the apparatus 125 at
a formed interconnection region 310, and then placing multiple
sectioned photovoltaic module assemblies in a pressure and heat
applying device (e.g., autoclave).
Finally, the process sequence may end with the edge seal(s) 301 and
junction box(es) 190 being attached to each of the laminated
photovoltaic module assemblies. In some embodiments, the materials
used to form the edge seal(s) 301 and bond the junction box(es) to
the laminated photovoltaic module assembly may be dispensed from a
device 188 disposed downstream of the lamination module 185.
Photovoltaic Module Assembly Configuration Examples
FIGS. 3A, 3B and 3C illustrate examples of various photovoltaic
module assembly configurations, such as the photovoltaic module
assemblies 300A, 300B and 300C that each include three, four or
five photovoltaic modules and have a length L.sub.1, L.sub.2 and
L.sub.3, respectively. One will appreciate that the configurations
of the photovoltaic module assemblies shown in FIGS. 3A-3C are not
intended to be limiting as to the scope of the disclosure provided
herein, since a photovoltaic module assembly may contain any number
of photovoltaic modules to achieve a desired power output. Thus, in
some cases a photovoltaic module assembly may contain at least two
photovoltaic modules, such as between about two and about twenty
five photovoltaic modules.
As shown in FIGS. 3A, 3B and 3C, each photovoltaic module assembly
contains a plurality of interconnected photovoltaic modules 110
that are disposed in an array and spaced apart by an
interconnection region 310, which is also referred to herein as a
gap, that is formed during the photovoltaic module assembly
formation process. The interconnection region 310 is generally
defined as an encapsulated region formed between adjacent
photovoltaic modules 110 through which the busbars 170 extend so as
to interconnect two adjacently positioned photovoltaic modules 110.
The busbars 170 are oriented such that they extend in a first
direction (i.e., X-direction) and are spaced apart a fixed distance
in a second direction (i.e., Y-direction) across the length L of
the photovoltaic module assembly. The fixed and regular orientation
of the busbars 170 allows photovoltaic module assemblies to be
easily interconnected with other similarly formed photovoltaic
module assemblies, and also allows components within a photovoltaic
module assembly to be easily replaced should one of the components
(e.g., photovoltaic modules) disposed therein become damaged during
manufacturing or use in the field, as will be discussed further
detail below.
In general, the photovoltaic module assemblies shown in FIGS. 3A,
3B and 3C contain the same components as the photovoltaic module
assembly 100 discussed above. However, the photovoltaic module
assemblies 300A, 300B and 300C each have a different number of
interconnected photovoltaic modules 110 so that a desired amount of
power can be generated by each photovoltaic module assembly. In
some embodiments, each of the photovoltaic modules 110 and formed
interconnection regions 310 are formed such that they have a
consistent fixed size so that multiple photovoltaic module
assemblies can be easily positioned in a desired regular array or
pattern across a roof, facade or other type of supporting element
on which the power generating photovoltaic module assemblies are
disposed. Typically, the spacing in the X-direction between the
edge of the substrate 111 in the photovoltaic module closest to the
end 102 (e.g., photovoltaic module 110A in FIG. 3C) and the end
102, and the spacing in the X-direction between the edge of the
substrate 111 in the photovoltaic module closest to the end 103
(e.g., photovoltaic module 110C in FIG. 3C) and the end 103, or
also referred to herein as the end lengths L.sub.A and L.sub.B
respectively, are each formed to a fixed or consistent size across
similarly formed photovoltaic module assemblies.
In some embodiments, depending on the number of photovoltaic
modules 110 and the size of the interconnection regions 310 each
photovoltaic module assembly will have a formed photovoltaic module
assembly length L that is set by the number of photovoltaic modules
disposed in the formed photovoltaic module assembly. In one
example, the photovoltaic module assembly 300C (FIG. 3C) includes
five photovoltaic modules 110A-110E that each have the same module
length L.sub.M, or distance edge-to-edge of a substrate 111 in the
X-direction, end lengths L.sub.A and L.sub.B, and four formed
interconnection regions 310 that each have the same gap length
L.sub.G, or distance between the adjacently disposed edges of the
substrates 111 in adjacent photovoltaic modules in the X-direction,
to achieve a photovoltaic module assembly length L.sub.3. In some
embodiments, the formed photovoltaic module assembly length L can
be determined by use of the equation:
L=L.sub.A+L.sub.B+N(L.sub.M)+(N-1)(L.sub.G), where N is equal to
the number of photovoltaic modules. Typically, the module length
L.sub.M is set by the electrical requirements of the photovoltaic
module assembly, the gap length L.sub.G may be between about 0.5 cm
and about 10 cm, the end length L.sub.A may be between about 0.5 cm
and about 5 cm, and end length L.sub.B may be between about 0.5 cm
and about 5 cm. In one example, the photovoltaic module assembly
length L may be greater than about 0.5 meters (m). In one example,
the photovoltaic module assembly length L may be about 10 m, 20 m,
40 m or greater.
In some embodiments, in which the photovoltaic module assembly
length L is an extended distance, such as lengths greater than 10
meters, the cross-sectional area of the busbars 170 may need to be
increased to reduce its electrical resistance and increase its
current carrying capacity across the extended length L of the
busbars 170. Thus, it is believed that by increasing the
cross-sectional area of each of the busbars 170 in an extended
length photovoltaic module assembly the power generated by
photovoltaic modules positioned at one end (e.g., end 102) of the
photovoltaic module assembly can be efficiently transferred to an
opposing end (e.g., end 103), on which the junction box is
positioned. However, due to the desire to form photovoltaic module
assemblies that are flexible, allow the photovoltaic module
assemblies to be formed by a roll-to-roll process, prevent the
larger cross-section busbars from encroaching the light receiving
surfaces of the photovoltaic modules 110, and/or not dramatically
increase the overall width (e.g., Y-direction) of the formed
photovoltaic module assemblies, the major current carrying regions
170A.sub.C, 170B.sub.C of larger cross-section busbars 170A', 170B'
may be disposed underneath each of the photovoltaic modules 110, as
shown in FIG. 3D. In this configuration, each of the larger
cross-section busbars 170A', 170B' include a connection region
170A.sub.A, 170B.sub.A, an interconnection region 170A.sub.B,
170B.sub.B and current carrying regions 170A.sub.C, 170B.sub.C,
respectively. In general, the connection regions 170A.sub.A,
170B.sub.A are formed such that they primarily contact the end
regions 108A, 108B of the photovoltaic modules 110, and the
interconnection region 170A.sub.B, 170B.sub.B is formed to
interconnect the connection region 170A.sub.A, 170B.sub.A with the
current carrying region 170A.sub.C, 170B.sub.C. In some
embodiments, the connection region 170A.sub.A, 170B.sub.A and
interconnection region 170A.sub.B, 170B.sub.B include a plurality
of thin and flexible conductive strips (e.g., thin in the
X-direction), or flexible wires, that are disposed at desired
intervals in the X-direction along the length of the extended
length photovoltaic module assembly. In other words, in some
embodiments, the connection regions 170A.sub.A, 170B.sub.A and
interconnection regions 170A.sub.B, 170B.sub.B do not extend the
complete length L of the photovoltaic module assembly in the
X-direction, and thus include discrete connections that are spaced
apart along the continuous length L of the current carrying regions
170A.sub.C, 170B.sub.C. In this case, the connection regions
170A.sub.A, 170B.sub.A and/or interconnection regions 170A.sub.B,
170B.sub.B of the larger cross-section busbars 170A', 170B' may
have a length that is between about 100 .mu.m to about 3
centimeters (cm) in the X-direction. In other configurations, the
connection regions 170A.sub.A, 170B.sub.A and/or interconnection
regions 170A.sub.B, 170B.sub.8 may have a length that is
substantially equal to the length of a sub-module in the
X-direction. The connection regions 170A.sub.A, 170B.sub.A may have
a width in the Y-direction (FIG. 3D) that is from about 100 .mu.m
to about 3 cm. The connection regions 170A.sub.A, 170B.sub.A and/or
interconnection regions 170A.sub.B, 170B.sub.B may have a thickness
in the Z-direction and Y-direction, respectively, from about 0.01
mm to about 2 mm, such as from about 0.1 mm to about 0.2 mm. The
current carrying regions 170A.sub.C, 170B.sub.C may have a length
that is substantially equal to the length L of the photovoltaic
module in the X-direction and a width in the Y-direction (FIG. 3D)
that is from about 4 mm to about 40 mm. Furthermore, the current
carrying regions 170A.sub.C, 170B.sub.C can have a thickness in the
Z-direction from about 0.01 mm to about 2 mm, such as from about
0.025 mm to about 0.5 mm, such as from about 0.1 mm to about 0.2
mm.
Interconnection and Rework Process Examples
As briefly discussed above, in some cases one or more of the
photovoltaic modules 110 in a photovoltaic module assembly may
become damaged during the photovoltaic module assembly
manufacturing process, during storage or transportation, or after
being placed in normal operation for a period of time. The presence
of a damaged photovoltaic module can render the complete
photovoltaic module assembly useless for its intended purpose. If a
photovoltaic module becomes inoperable in a conventional
photovoltaic module assembly it would cause the complete
conventional photovoltaic module assembly to be scrapped, thus
creating a significant scrap cost and significant amount of waste
due to need to also throwaway functioning photovoltaic modules and
other useful components. Therefore, there is a need for the
photovoltaic module assembly described herein, which can be
reworked to make it functional again.
In one example, a photovoltaic module assembly 400A, as shown in
FIG. 4A, includes five photovoltaic modules 110A-110E and one of
the photovoltaic modules, such as photovoltaic module 110C, is not
functioning properly and thus needs to be removed from the
photovoltaic module assembly 400A. The process of removing the
problematic photovoltaic module 110C from the photovoltaic module
assembly 400A may include the following steps.
First, as shown in FIG. 4B, the damaged photovoltaic module 110C is
removed from the photovoltaic module assembly 400A. In this
example, the damaged photovoltaic module 110C is removed by
sectioning or cutting through the various layers and components
within the photovoltaic module assembly in the space found within
the interconnection regions 310B and 310C, which are formed on
either side of the damaged photovoltaic module 110C. In
configurations where the photovoltaic module assembly includes one
or more of the flexible photovoltaic module assembly components,
such as a flexible front sheet 151 and flexible back sheet 109, the
sectioning process may be easily performed by use of a blade,
scissors, shears, a cut-off saw or other similar cutting device.
The process of removing the damaged photovoltaic module 110C can be
completed such that the multiple busbars 170, such as busbars 170A
and 170B, are at least partially exposed in the remaining portions
of the photovoltaic module assembly 400A. In some configurations,
the cut formed during the sectioning process is made outside of a
module edge seal (not shown). The module edge seal is separately
disposed around the edges of each photovoltaic module 110 (e.g.,
module edge seal is disposed in the X-Y plane) and between the
front sheet 151 and back sheet 109 within the photovoltaic module
assembly. The module edge seal may be formed from the same material
as the edge seal 310 described above.
Next, as shown in FIG. 4C, once the damaged photovoltaic module
110C has been removed the remaining portions of the photovoltaic
module assembly 400A can be joined together to form a functioning
reworked photovoltaic module assembly 400B. The region of the
reworked photovoltaic module assembly 400B where the remaining
portions of the photovoltaic module assembly 400A are connected is
referred to herein as a junction 410. The process of forming the
junction 410 will typically include electrically connecting (e.g.,
soldering, tack welding, etc.) the sectioned portions of the busbar
170A, such as busbar section 170A.sub.1 from the left portion and
busbar section 170A.sub.2 from the right portion, and connecting
the sectioned portions of the busbar 170B, such as busbar section
170B.sub.1 from the left portion and busbar section 170B.sub.2 from
the right portion. The process of joining the remaining portions of
the photovoltaic module assembly 400A may also include delivering
energy to the various components found at the junction 410, such as
the front-side adhesive 101A and the back-side adhesive 101B in
both portions of the photovoltaic module assembly 400B, to form an
environmental seal at the junction 410.
FIG. 5A illustrates one possible configuration of the remaining
portions of the photovoltaic module assembly 400A after the damaged
photovoltaic module 110C has been removed. During the process of
sectioning or cutting through the interconnection regions 310B and
310C of the photovoltaic module assembly an edge configuration that
will allow the remaining portions of the photovoltaic module
assembly 400A to be easily connected together is formed. In this
case, the left remaining portion 500A of the photovoltaic module
assembly 400A contains a "step" configuration in which the busbars
170A.sub.1 and 170B.sub.1 are both exposed and supported vertically
(i.e., Z-direction) by back-side adhesive 101B, and the right
remaining portion 500B of the photovoltaic module assembly 400A
contains an "inverted step" configuration in which the busbars
170A.sub.2 and 170B.sub.2 are both exposed and supported vertically
by the front-side adhesive 101A. The process of forming the edge
configurations shown in FIG. 5A may be completed by removing the
unwanted layers from each end configuration. For example, the
"step" configuration formed in the left remaining portion 500A may
be formed by removing a portion of the front-side adhesive 101A and
front sheet 151 by use of blade, saw or other form of cutting
tool.
FIG. 5B illustrates one example of a junction 410 that has been
formed using the step and inverted step configuration shown in FIG.
5A. In this example, the step and inverted step configurations
found in the left remaining portion 500A and the right remaining
portion 500B, respectively, are positioned to overlap each other to
form an electrical connection between the exposed portions of the
busbars 170. For example, the busbar section 170A.sub.1 and busbar
section 170A.sub.2 are electrically connected together, and the
busbar section 170B.sub.1 and busbar section 170B.sub.2 are
electrically connected together by use of a conductive adhesive, or
are soldered or welded together. In some embodiments, a sealing
material 510 may be disposed over both of the edges of the left
remaining portion 500A and the right remaining portion 500B of the
junction 410 to prevent environmental attack of the components
found within the formed reworked photovoltaic module assembly. In
some configurations, it is desirable to dispense or position the
sealing material 510 such that it is disposed over both of the
edges of the left remaining portion 500A and the right remaining
portion 500B and also into a gap formed between the opposing walls
of the left remaining portion 500A and the right remaining portion
500B in the junction 410 region. In one configuration, the sealing
material 510 is dispensed such that it will not interfere with the
busbar connections (e.g., electrical connections formed between
busbar section 170A.sub.1 and busbar section 170A.sub.2 and the
busbar section 170B.sub.1 and busbar section 170B.sub.2), but is in
contact with at least a portion of each of the opposing walls found
in the junction 410 region. The sealing material 510 may include
the same materials used to form the edge seal(s) 301, which are
discussed above. The sealing material 510 may include a sealing
component and/or an adhesive component that are formed from two
separate materials. In one embodiment, the sealing component
includes a dispensable material that is useful as a barrier to
prevent the diffusion of environmental contaminants into the
photovoltaic module assembly, and the adhesive component includes a
dispensable material that is useful for bonding portions of the
junction 410 together.
In some embodiments, at least a portion of the junction 410, such
as a region on a non-sunny side of the photovoltaic module
assembly, is additionally supported by the placement of a section
of a supporting material (e.g., section of back sheet material or
other similar material) that is bonded across the joint 410 formed
in the photovoltaic module assembly. In one example, a piece of
back sheet 109 is bonded across the junction 410, such that it
covers at least a portion of the left remaining portion 500A and
the right remaining portion 500B. In some cases, the additional
supporting material is positioned to overlap the sealing material
510.
FIG. 5C illustrates another example of a junction 410 that can be
formed to interconnect the remaining portions of a photovoltaic
module assembly. In this example, the edges of the left remaining
portion 500A and the right remaining portion 500B are formed by
using a cutting tool that can cut in a vertical direction through
the interconnection regions to form the vertical walls 505. In this
example, the busbar section 170A.sub.1 and busbar section
170A.sub.2 are electrically connected together, and the busbar
section 170B.sub.1 and busbar section 170B.sub.2 are electrically
connected together when the vertical walls 505 are brought
together. In some cases, the busbars 170 may each be electrically
connected together at a connection point 525 by use of a conductive
adhesive or thermal bonding process. In some embodiments, a sealing
material 510 may be disposed over the edges of the left remaining
portion 500A and the right remaining portion 500B of the junction
410 to prevent environmental attack of the components found within
the formed reworked photovoltaic module assembly. As noted above,
in one configuration, the sealing material 510 is dispensed such
that it will not interfere with the busbar connections, but is
positioned such that the sealing material 510 is in contact with at
least a portion of each of the vertical walls 505 found in the
junction 410 region.
While FIGS. 4A-4C and 5A-5C illustrate a process of removing a
damaged photovoltaic module and forming a new photovoltaic module
assembly that has fewer photovoltaic modules than the original
photovoltaic module assembly, this process is not intended to be
limiting as to the scope of the disclosure provided herein, since
the process of removing the problematic photovoltaic module may
alternately include replacing the problematic photovoltaic module
110C with a new undamaged photovoltaic module (not shown). In this
case, two junctions 410 are formed on either side of the new
undamaged photovoltaic module 110 to connect the remaining portions
of the photovoltaic module assembly 400A and the new undamaged
photovoltaic module 110 together. Therefore, the length of the
photovoltaic module assembly 400A need not change from its original
size and the power output from the reformed photovoltaic module
assembly need not change from its original designed configuration.
One will note that it is also generally desirable to replace the
damaged photovoltaic module with a new photovoltaic module that has
the same performance characteristics (e.g., conversion efficiency
(CE), series resistance (R.sub.s), fill factor (FF), etc.) to
assure that the newly formed photovoltaic module assembly has
desirable performance characteristics.
One will appreciate that one or more of the end configurations
discussed above in conjunction with FIGS. 5A-5C can also be used to
interconnect two photovoltaic module assemblies to form a series
connected array of photovoltaic module assemblies. In one example,
the left remaining portion 500A shown in FIG. 5A may be the end 103
of a first photovoltaic module assembly and the right remaining
portion 500B may be the end 102 of a second photovoltaic module
assembly, so that the first and second photovoltaic module
assemblies can be easily connected together by joining the ends 102
and 103 of the first and second photovoltaic module assemblies, as
similarly shown in FIG. 5B. In some embodiments, a sealing material
(e.g., sealing material 510) may be disposed over the ends 102 and
103 of the series connected first and second photovoltaic module
assemblies to prevent environmental attack of the photovoltaic
modules and other electrical components found within both of the
photovoltaic module assemblies.
While the foregoing is directed to embodiments of the present
disclosure, other and further embodiments of the disclosure may be
devised without departing from the basic scope thereof, and the
scope thereof is determined by the claims that follow.
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